or if you are allergic to trulicity or its ingredients. stop using trulicity and your doctor right away if you have symptoms of an allergic reaction, such as itching, rash, or difficulty breathing; if you have signs of pancreatitis, such as severe stomach pain that will not go away and may move to your back, with or without vomiting or if you have symptoms of thyroid cancer, which may include a lump or swelling in your neck, hoarseness, trouble swallowing, or shortness of breath. medicines like trulicity may cause stomach problems, which could be severe. tell your doctor about all your medical conditions and any medicines you take. taking trulicity with a sulfonylurea or insulin may increase your risk for low blood sugar. common side effects include nausea, diarrhea, vomiting, decreased appetite, and indigestion. some side effects can lead to dehydration, which may cause kidney failure. with trulicity, i click to activate what's within me. if you want help improving your a1c and blood sugar numbers with a non-insulin option, click to activate your within. ask your doctor about once-weekly trulicity.